PARIS, May 6 (Reuters) - French investment bank Natixis on Thursday posted a first quarter net profit of 225 million euros, recovering from a loss a year ago, but expressed caution on pandemic-related provisions for bad loans.

Despite a drop in the cost of risk in the first three months of the year, the lender said provisions were still at elevated levels with impairments coming from the tourism and aviation sectors.

"We must remain cautious regarding the cost of risk," CEO Nicolas Namias told reporters, as companies hit by the pandemic crisis could still need further support from banks in post-COVID-19 economic recovery.

Natixis said in a statement that the cost of risk amounted to 92 million euros in the quarter, down from 193 million euros in Q1 2020.

In its corporate and investment banking business, revenue was up 38% to 940 million euros ($1.13 billion) while revenue rose 11% in asset and wealth management.

Its parent company BPCE, a co-operative bank, said in February it planned to buy the 29.3% stake in Natixis it does not already own, with a view to delisting the investment bank and restructuring some of its activities.

BPCE chief executive Laurent Mignon said the bank expected to launch the offer in June once it gets all regulatory approvals, with closure of the bid in early July.

($1 = 0.8299 euros) (Reporting by Matthieu Protard; Editing by Elaine Hardcastle, Kirsten Donovan)