Beach Energy Ltd (ASX: BPT) saw its stock plummet by 5% during Monday's intraday trading, as the energy sector reeled from OPEC+'s surprise announcement to increase oil production. The decision has sent shockwaves through the global oil market, causing Brent crude prices to tumble and putting significant pressure on oil and gas companies.

The Organization of the Petroleum Exporting Countries and its allies (OPEC+) revealed plans to boost oil output by 400,000 barrels per day starting in June. This unexpected move has led to a sharp decline in oil prices, with Brent crude falling 3.4% to US$59.20 per barrel. The impact was felt across the Australian energy sector, with the S&P/ASX 200 Energy Index dropping 2.4%, significantly underperforming the broader market.

Analysts suggest that Saudi Arabia's decision to increase production is aimed at disciplining OPEC members who have been exceeding their quotas. The move also aligns with U.S. President Donald Trump's push for lower oil prices. While this may benefit consumers, it has clearly rattled investors in oil and gas companies like Beach Energy. As the market digests the implications of OPEC+'s decision, Beach Energy and its peers in the ASX 200 energy sector may continue to face headwinds in the near term.