Nov 6 (Reuters) - Charles Schwab on Thursday agreed to buy private shares platform Forge Global, in a deal valued at $660 million as Wall Street firms seek to meet growing investor demand for access to high-growth startups.

Major financial institutions are expanding services that give clients access to private companies and liquidity in pre-IPO shares, seeking to tap rising investor demand for early exposure to fast-growing startups.

The per-share deal value of $45, represents a premium of roughly 72% over the stock's last closing price. Shares of Forge Global surged 67% in premarket trading on the news.

Some of the world's most valuable startups are choosing to stay private for longer, raising capital in private markets rather than pursuing initial public offerings.

Companies such as ChatGPT-maker OpenAI, Elon Musk's SpaceX and TikTok-parent Bytedance now hold valuations that rival or exceed several major S&P 500 companies, narrowing the gap in influence between public and private markets.

Investors are seeking exposure to these fast-growing companies, and financial services firms are moving to cater to that demand.

Last month, Wall Street giant Morgan Stanley agreed to acquire private shares platform EquityZen, a rival to Forge Global.

Forge Global went public in 2021 through a blank-check deal with a special purpose acquisition company. Its stock has jumped 87% this year amid media reports that the company had put itself up for sale and received takeover proposals.

It operates a trading marketplace through which investors have bought and sold more than $17 billion in private company shares.

Charles Schwab offers wealth management, securities brokerage, banking and financial advisory services to customers. It has a market capitalization of roughly $170 billion and manages around $11.6 trillion in client assets.

The companies expect the deal to close in the first half of 2026.