Great Portland Estates provided some much-needed cheer to the listed property sector today when it revealed that its London West End-dominated portfolio is weathering the storm.

Half-year results to 30 September revealed an 11% increase in net asset value to 660p a share, with 8% coming in the first three months and 3% coming in the second quarter, during which the credit crunch began. The value of Great Portland’s portfolio held throughout the six months increased by 8.9%, which included a 2.8% rise in the second quarter. Including purchases and share of joint ventures the portfolio’s total value was £1.75bn.

The news went down well in the City, which marked Great Portland’s shares up 3.7%, or 19p, to 535p. ‘These are strong interim results in every respect,’ said Lehman Brothers analyst Chet Riley.

The valuation uplift was due to asset management and rental value growth outweighing a rise in yields. The equivalent yield increased by 10 basis points over the first half to 5%. Stripping out development properties and cases of major asset repositioning that have driven yields lower and asset values sharply higher, the portfolio equivalent yield was around 20 basis points higher.

Chief executive Toby Courtauld forecast that the company’s equivalent yield could rise a further 25 basis points to 5.25%, which would be above the 30-year average in the West End of 5%.