During European morning trade, the EURO STOXX 50 climbed 0.88%, France’s CAC 40 rallied 0.98%, while Germany’s DAX 30 advanced 0.78%.
The ECB was expected to leave interest rates on hold on Thursday and to reiterate that an exit from loose monetary policy remains distant.
Meanwhile, concerns over political instability in Portugal continued to weigh on market sentiment following the resignation of country’s foreign minister on Tuesday and the finance minister on Monday in protest over government austerity policies.
The political crisis raised doubts over the future of the country's coalition government and its ability to honor bailout commitments.
Investors were also looking ahead to Friday’s U.S. nonfarm payrolls data, for further clues on when the Federal Reserve may decide to unwind its USD85 billion-a-month stimulus program.
Financial stocks were broadly higher, as French lenders BNP Paribas and Societe Generale advanced 0.64% and 0.87%, while Germany's Deutsche Bank added 0.10%.
Peripheral lenders added to gains, with Spanish banks Banco Santander and BBVA climbing 0.81% and 0.78% respectively, while Italy's Unicredit and Intesa Sanpaolo radvanced 0.51% and 0.90%.
Elsewhere, OC Oerlikon rallied 1.33% after it completed the sale of its natural-fibers business.
In London, FTSE 100 jumped 0.93%, as U.K. lenders tracked their European counterparts higher.
Shares in the Royal Bank of Scotland advanced 0.91% and Barclays rallied 1.65%, while HSBC Holdings and Lloyds Banking surged 1.06% and 3.75% respectively.
Mining giants BHP Billiton and Rio Tinto were also on the upside, recovering from the previous day's shapr losses, with shares up 1.33% and 2.57%, while Anglo American jumped 1.53% and Polymetal climbed 1.33%.
Meanwhile, Taylor Wimpey saw shares soar 2.99% after the U.K. housebuilder said its operating profit margin increased in the first half.
In the U.S., equity markets were to remain closed for the Independence Day holiday.
The Bank of England was to conclude its first policy meeting under the leadership of new Governor Mark Carney later in the day, and was expected to keep benchmark interest rates unchanged.