Aegon, the Dutch insurer, has promised to do all it can to avoid a rights issue as it pursues measures to bolster its capital base without diluting the value of shares.

The group said on Thursday it expected impairments of €275m ($374.9m) in the third quarter, up from €98m in the second quarter, mostly due to its US credit portfolio and exposure to Lehman Brothers, Washington Mutual and AIG. It expects to maintain its AA credit rating, which is necessary for some of its activities.