MILAN (Reuters) -Prada reported on Wednesday a 9% increase in first half net revenues at constant currencies, defying the weak sector trend thanks to its smaller but fast expanding Miu Miu brand, while its main eponymous label lagged behind.

Net revenue at the family-owned group, which will soon include Versace, totalled 2.74 billion euros ($3.16 billion), broadly in line with a Visible Alpha analysts' consensus, with growth supported by all regions.

Retail sales at the Prada brand fell 3.6% in the second quarter alone, while they rose 40% at the Miu Miu brand, which last year accounted for a quarter of the group's total revenues.

Last month the Italian luxury group parted company with Prada's brand CEO Gianfranco D'Attis.

The group's adjusted operating profit rose 8% to 619 million euros in the six months, below the 636 million euro operating EBIT seen in an analyst consensus provided by Visible Alpha.

"This healthy performance was achieved against a challenging backdrop, somewhat unprecedented in our industry," said Prada Chairman Patrizio Bertelli in a statement.

"We believe the structural growth opportunities remain unchanged, but we are conscious that in the short term we may continue to face a turbulent economic environment," he added.

The group reaffirmed that it expected the closing of the Versace acquisition, agreed in April, in the second half of the year.

A recovery for the luxury industry remains elusive.

Gucci owner Kering reported on Tuesday a 15% drop in quarterly revenues, while last week luxury bellwether LVMH reported a slightly worse than expected 4% decline in quarterly sales.

French luxury group Hermes, which reported a rise of 9% in quarterly sales, also showed some signs it is not totally immune to a wider luxury downturn.

($1 = 0.8672 euros)