Updates throughout with Apple bond sale and commentary in paragraphs 1-2, 7, 11 & 13

By Shankar Ramakrishnan and Matt Tracy

May 5 (Reuters) - Apple AAPL.O sold $4.5 billion worth of bonds late on Monday, its first offering in two years, and said it plans to use proceeds to repurchase stock and repay outstanding debt.

The offering included $1.5 billion of three-year notes and $1 billion each of five, seven- and 10-year notes. Apple has $8 billion in debt maturing from May through November.

Eight other issuers in the investment-grade primary market also kicked off an unusually active week with an estimated total of nearly $35 billion of new debt offerings. These include notes from Comcast CMCSA.O, DTE Electric Co DTEED.UL and General Motors GM.N.

New bond supply is rising as credit spreads, or the premium companies pay over Treasuries, have rebounded in the weeks since U.S. President Donald Trump first announced harsh tariffs and then provided temporary relief.

Many issuers had planned offerings sooner but were thrown off by the uncertainty of Trump's policies. They are rushing to market before the Federal Reserve meets on Wednesday to avoid the volatility that usually follows the Fed chair's comments after such monthly policymaking meetings.

Demand is expected to remain strong as uncertainty pushed investors to seek safety in higher-rated bonds, analysts said.

Apple's debt sale had order books well over the amount it sought, a source familiar with the matter said, noting that orders totaled $10 billion.

The issuance rush follows six consecutive weeks of outflows from investment-grade funds, the longest streak since November 2022, noted Dan Krieter, director of fixed income strategy at BMO Capital Markets.

"It's a pretty attractive space to lock in these all-in yields," said Natalie Trevithick, head of investment grade credit strategy at Los Angeles-based asset manager Payden & Rygel.

"The issuance is a lot of high-quality names today, (and) a lot of it is just regularly planned issuance. There are probably a couple deals that got pushed back from April," Trevithick noted.

Apple likely timed its bond sale to take advantage of tightening investment-grade bond spreads since Trump announced he would ease tariffs on various countries late last month.

The average investment-grade bond spread was 106 basis points on Friday, the latest data shows, or three basis points below levels touched the day before. .MERC0A0

"Apple does tend to be pretty good at timing their deals around tight (spreads)," said a second investor, who declined to be named commenting on specific offerings.

Payden & Rygel expects $12 billion to $13 billion of supply on Monday, with roughly $58 billion of investor demand, she added.

(Reporting by Shankar Ramakrishnan and Matt Tracy; Editing by David Gregorio and Richard Chang)

((Shankar.Ramakrishnan@thomsonreuters.com; +1 2017590156))